app.py

import gradio as gr
import os
import openai
import pandas as pd
from langchain.vectorstores import FAISS
from langchain.prompts import ChatPromptTemplate, SystemMessagePromptTemplate, HumanMessagePromptTemplate
from langchain.chains import LLMChain
from langchain_core.output_parsers.string import StrOutputParser
from langchain.chat_models import ChatOpenAI
from langchain.embeddings.openai import OpenAIEmbeddings
#from langchain.embeddings import HuggingFaceBgeEmbeddings
import nltk
nltk.download('wordnet')

from sentence_transformers import SentenceTransformer

#embeddings = OpenAIEmbeddings()
#model_name = "BAAI/bge-large-en-v1.5"
#model_kwargs = {'device':'cuda'}
#encode_kwargs = {'normalize_embeddings':True}

#embedding_function = HuggingFaceBgeEmbeddings(
#    model_name = model_name,
#    model_kwargs = model_kwargs,
#    encode_kwargs = encode_kwargs
#)

embedder = SentenceTransformer('all-mpnet-base-v2')

# Set the OpenAI API key
#openai.api_key = os.getenv("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")

# Load the FAISS index using LangChain's FAISS implementation
db = FAISS.load_local("Faiss_index", embedder, allow_dangerous_deserialization=True)
parser = StrOutputParser()

# Load your data (e.g., a DataFrame)
df = pd.read_pickle('df_news (1).pkl')

# Search function to retrieve relevant documents
def search(query):
    query_embedding = embedder.embed_query(query).reshape(1, -1).astype('float32')
    D, I = db.similarity_search_with_score(query_embedding, k=10)
    results = []
    for idx in I[0]:
        if idx < 3327:  # Adjust this based on your indexing
            doc_index = idx
            results.append({
                'type': 'metadata',
                'title': df.iloc[doc_index]['title'],
                'author': df.iloc[doc_index]['author'],
                'full_text': df.iloc[doc_index]['full_text'],
                'source': df.iloc[doc_index]['url']
            })
        else:
            chunk_index = idx - 3327
            metadata = metadata_info[chunk_index]
            doc_index = metadata['index']
            chunk_text = metadata['chunk']
            results.append({
                'type': 'content',
                'title': df.iloc[doc_index]['title'],
                'author': df.iloc[doc_index]['author'],
                'content': chunk_text,
                'source': df.iloc[doc_index]['url']
            })

    return results

# Generate an answer based on the retrieved documents
def generate_answer(query):
    context = search(query)
    context_str = "\n\n".join([f"Title: {doc['title']}\nContent: {doc.get('content', doc.get('full_text', ''))}" for doc in context])

    prompt = f"""
    Answer the question based on the context below. If you can't answer the question, answer with "I don't know".
    Context: {context_str}
    Question: {query}
    """

    # Set up the ChatOpenAI model with temperature and other parameters
    chat = ChatOpenAI(
        model="gpt-4",
        temperature=0.2,
        max_tokens=1500,
        api_key=openai.api_key
    )

    messages = [
        SystemMessagePromptTemplate.from_template("You are a helpful assistant."),
        HumanMessagePromptTemplate.from_template(prompt)
    ]

    chat_chain = LLMChain(
        llm=chat,
        prompt=ChatPromptTemplate.from_messages(messages)
    )

    # Get the response from the chat model
    response = chat_chain.run(messages)
    return response.strip()

# Gradio chat interface
def respond(message, history, system_message, max_tokens, temperature, top_p):
    response = generate_answer(message)
    yield response

# Gradio demo setup
demo = gr.ChatInterface(
    respond,
    additional_inputs=[
        gr.Textbox(value="You are a friendly Chatbot.", label="System message"),
        gr.Slider(minimum=1, maximum=2048, value=512, step=1, label="Max new tokens"),
        gr.Slider(minimum=0.1, maximum=4.0, value=0.7, step=0.1, label="Temperature"),
        gr.Slider(minimum=0.1, maximum=1.0, value=0.95, step=0.05, label="Top-p (nucleus sampling)"),
    ],
)

if __name__ == "__main__":
    demo.launch()